ZBA31: an advanced mask writer meeting the demands of the 1-gigabit DRAM generation

It is now widely accepted that variable shaped beam ( VSB ) writers have some significant advantages compared to the gaussian principle systems, especially when throughput is considered. The ZBA variable shaped beam system introduced in this paper is the most advanced mask generator from Jenoptik Germany. We have utilized the VSB electron optical concept from the very beginning of designing e-beam systems of the ZBA-series more than 20 years ago. The unique combination of this longstanding experience, more than 120 systems were constructed and comissioned, with some very recent developments in the software and operation logistics of the system, allow the ZBA31H maskwriter system to provide the complete performance that is required to satisfy the demands of the 1 G-DRAM generation masks.